Indicating electrical fuse plug



Feb. 3, 1931'.v B. E. RUTLEDGE 1,791,287

INDICATING 4ELECTRICAI.: FUSE PLUG Filed sept. so. 1929 Fm. l im z INVENTOR.

v5U? E. .Qu/edge BY 9,

ATTORNEY.

Patented Feb. 3, 1931 PATENT OFFICE BIBL E. RUTLEDGE, OF EL DORADO, KANSAS INDICATING ELECTRICAL FUSE PLUG Application. led September 30, 1929.

This invention relates to an indicating electric plug fuse.

The object of this invention is to provide a fuse whose appearance readily and deiinitely shows whether or not the fuse has been blown.

A further object of my invention is to provide a plug having a fuse link with an intermediate portion reduced as a means to insure fusion at the reduced portion when the plug is blown.

A still further object of my invention is to provide a plug having a spring actuated indicator with an arm positioned to engage against the reduced portion of the link so that when the plug is blown the arm will be released at which time the spring will cause the indicator to rotate approximately a quadrant of its sweep.

A still further object of my invention is to properly trunnion the indicator concentric to the axis of the plug.

rllhese and other objects will be more fully explained as this description progresses, reference being had to the accompanying drawings forming a part of this specification and in which like characters will apply to like parts in the different views.

Referring to the drawings, Fig. 1 is a plan view showing the appearance of the plug before the fuse has been blown. Fig. 2 is a plan view of the base of the plug showing the position of the indicator after the fuse has been blown. Fig. 8 is a sectional view taken along line III-III in Fig. 1. Fig. 4 is a sectional view taken along line IV-IV in Fig. 3. Fig. 5 is a sectional view taken along line VV in Fig. 3. Fig. 6 is a bottom plan view of the plug.

At 10 is shown the usual plug body carrying the metallic threaded member 11, the body 10 being made hollow and containing a stop member 24, and containing the fusible link 12 connecting the metallic member 11 and the metallic pin 13, which is provided with an extension as a contact point of the plug shown at 14. The fusible link 12 is provided with a reduced portion 15 at which point the fuse will sever under an excess load of electric current. The upper portion of the Serial No. 396,074.

body 10 is fashioned with a recessed polygonal form, whose sides are slightly tapered as shown at 16. At 17'is shown a polyhedron having slightly tapered sides adapted to fit into the recess just described, and when forced downward therein the polyhedron is brought to snug engagement against outward movement and rotation by reason of the polygonal and tapered form. Within the upper face of the polyhedron is a countersunk portion to receive a disc 18, diametrically positioned and adapted to align with depressions 20 in the polyhedron 17. The disc 18 is rigidly attached to a shaft 21 which is revolvably mounted on the central axis of the polyhedron 17. The said shaft 21 has a right angle bend as at 22 so thatthe extreme outer end thereof will engage against the side of the fusible link at its reduced portion 15. On the shaft 21 is wound a spring 23 one end of which is attached to the member 17 and the other end having a hook to engage on the arm portion of the shaft 21 which tends to rotate the shaft when the link is blown, the rotation thereof being checked by the arm contacting with the stop member 24.

In assembling this plug above described,` the disc 18 and the shaft 2l are rotated against the pressure of the spring 23 and then the member 17 is seated in the member 10 so that the arm of the shaft 21 contacts the fusible link at the point 15 at which time the marked portion 19 on the disc 18 is in alignnrizent with the portions 2O on the polyhedron 1 The operation of the fuse plug is as follows: When the fuse is subjected to an overload, the fusible link will melt at its reduced portion at which time the arm in contact therewith will release and allowing the shaft and disc to rotate by reason of the spring tension and stopped at a transverse position so that the depressed portion 19 is at right angles to the depressed portions 20 thereby indicating the fusible link is severed, breaking the circuit.

The indicator of the plug is shown and described to rotate a quadrant. This however may be varied in its travel.

I do not wish to be confined to the exact disclosure, and such other modifications may be employed as lie within the scope of the appended claims, and what I claim as new and desire to secure by Letters Patent is:

5 l. In a fuse plug, a plug of the class described, a hollow body portion and a polyhedron to close the outer end of the hollow of the plug body, an indicator comprising a shaft, being trunnioned in the polyhedron,

lo a disc on the outer end of the shaft, the disc having depressed channel Vdianietrically positioned thereon depressed marks diametrically positioned on the outer surface of the polyhedron, and registry with their respective ends of the channel, an arm onthe inner end of the shaft, the arln transversely eX- tending and integrally connected to the shaft, a fuse link in the hollow of the plug body, the said fuse link having a reduced portion cross sectionally and arranged to function as a detent for the arin against rotation, a spring coiled about the shaft and being so connected to cause rotation when the link is severed. I

2. In a fuse plug as an article of rnanu facture, a hollow body with a fusible link positioned near the side wall of the hollow; a shaft axially positioned to the'hollow and a recessed and apertured polyhedron, the

shaft trunnioned in the aperture, a right angle positioned arm on one end of the shaft, a coiled spring positioned on the shaft, one end of the spring being attached to the arni and the other end secured to the polyhedron as rotating means for the shaft when the spring is wound, the arin of the shaft to Contact with the side of the link to prevent rotation of the shaft, a dise on the outer end of the shaft, the disc positioned in the recess of the poly-V 0 hedron and rotatable` therein with the sha-ft,

the polyhedron having a pair of marks diametrically positionedthereon, the disc having a depression.

In testimony whereof I affix my signature.

i5 BinL E. RUT'Lnnon. 

